I think they can be a little more complex than that. When creating a GIF in GIMP, there is a function to “Optimize” which gets rid of redundant pixels that are the exact same on multiple frames (or something like that). Whatever it does, it definitely reduces the final file size. Any time I make an animation that has to be a GIF file for whatever reason, I try to make it in GIMP to make use of that feature.
I think they can be a little more complex than that. When creating a GIF in GIMP, there is a function to “Optimize” which gets rid of redundant pixels that are the exact same on multiple frames (or something like that). Whatever it does, it definitely reduces the final file size. Any time I make an animation that has to be a GIF file for whatever reason, I try to make it in GIMP to make use of that feature.
https://docs.gimp.org/3.0/en/plug-in-optimize.html